Over the past decade,electric vehicles(EVs)have been considered in a growing number of models and methods for vehicle routing problems(VRPs).This study presents a comprehensive survey of EV routing problems and their ...Over the past decade,electric vehicles(EVs)have been considered in a growing number of models and methods for vehicle routing problems(VRPs).This study presents a comprehensive survey of EV routing problems and their many variants.We only consider the problems in which each vehicle may visit multiple vertices and be recharged during the trip.The related literature can be roughly divided into nine classes:Electric traveling salesman problem,green VRP,electric VRP,mixed electric VRP,electric location routing problem,hybrid electric VRP,electric dial-a-ride problem,electric two-echelon VRP,and electric pickup and delivery problem.For each of these nine classes,we focus on reviewing the settings of problem variants and the algorithms used to obtain their solutions.展开更多
Radio frequency(RF) self-interference is a key issue for the application of in-band full-duplex communication in beyond fifth generation and sixth generation communications.Compared with electronic technology, photoni...Radio frequency(RF) self-interference is a key issue for the application of in-band full-duplex communication in beyond fifth generation and sixth generation communications.Compared with electronic technology, photonic technology has the advantages of wide bandwidth and high tuning precision, exhibiting great potential to realize high interference cancellation depth over broad band.In this paper, a comprehensive overview of photonic enabled RF self-interference cancellation(SIC)is presented.The operation principle of photonic RF SIC is introduced, and the advances in implementing photonic RF SIC according to the realization mechanism of phase reversal are summarized.For further realistic applications, the multipath RF SIC and the integrated photonic RF SIC are also surveyed.Finally, the challenges and opportunities of photonic RF SIC technology are discussed.展开更多
In-band full-duplex(IBFD) technology can double the spectrum utilization efficiency for wireless communications,and increase the data transmission rate of B5G and 6G networks and satellite communications. RF self-inte...In-band full-duplex(IBFD) technology can double the spectrum utilization efficiency for wireless communications,and increase the data transmission rate of B5G and 6G networks and satellite communications. RF self-interference is the major challenge for the application of IBFD technology, which must be resolved. Compared with the conventional electronic method, the photonic self-interference cancellation(PSIC) technique has the advantages of wide bandwidth, high amplitude and time delay tuning precision, and immunity to electromagnetic interference.Integrating the PSIC system on chip can effectively reduce the size, weight, and power consumption and meet the application requirement, especially for mobile terminals and small satellite payloads. In this paper, the silicon integrated PSIC chip is presented first and demonstrated for IBFD communication. The integrated PSIC chip comprises function units including phase modulation, time delay and amplitude tuning, sideband filtering, and photodetection, which complete the matching conditions for RF self-interference cancellation. Over the wide frequency range of C, X, Ku, and K bands, from 5 GHz to 25 GHz, a cancellation depth of more than 20 dB is achieved with the narrowest bandwidth of 140 MHz. A maximum bandwidth of 630 MHz is obtained at a center frequency of10 GHz. The full-duplex communication experiment at Ku-band by using the PSIC chip is carried out. Cancellation depths of 24.9 dB and 26.6 dB are measured for a bandwidth of 100 MHz at central frequencies of 12.4 GHz and14.2 GHz, respectively, and the signal of interest(SOI) with 16-quadrature amplitude modulation is recovered successfully. The factors affecting the cancellation depth and maximum interference to the SOI ratio are investigated in detail. The performances of the integrated PSIC system including link gain, noise figure, receiving sensitivity, and spurious free dynamic range are characterized.展开更多
Compared with the traditional frequency division duplex and time division duplex,the in-band full-duplex(IBFD)technology can double the spectrum utilization efficiency and information transmission rate.However,radio f...Compared with the traditional frequency division duplex and time division duplex,the in-band full-duplex(IBFD)technology can double the spectrum utilization efficiency and information transmission rate.However,radio frequency(RF)self-interference remains a key issue to be resolved for the application of IBFD.The photonic RF self-interference cancellation(SIC)scheme is endowed with the advantages of wide bandwidth,high amplitude and time delay tuning precision,and immunity to electromagnetic interference.To meet the requirements of the new generation of mobile terminals and satellite payloads,the photonic RF SIC system is desired to be miniaturized,integrated,and low power consumption.In this study,the integrated photonic RF SIC scheme was proposed and demonstrated on a silicon-based platform.By utilizing the opposite bias points of the on-chip dual Mach-Zehnder modulators,the phase inversion relationship for SIC was realized over a broad frequency band.The time delay structure combining the optically switched waveguide and compact spiral waveguide enables continuous tuning of time over a wide bandwidth.The optical amplitude adjuster provides efficient amplitude control with a large dynamic range.After being packaged with optical,direct current,and RF design,the photonic RF SIC chip exhibits the interference cancellation capabilities across L,S,C,X,Ku,K,and Ka bands.In the S and C bands,a cancellation depth exceeding 20 dB was measured across a bandwidth of 4.8 GHz.An impressive cancellation depth of over 40 dB was achieved within a bandwidth of 80 MHz at a central frequency of 2 GHz.For the application of over-the-air IBFD communication at the newly promulgated center frequency of 6 GHz for 5G communication,the cancellation depth of 21.7 dB was demonstrated in the bandwidth of 100 MHz,and the low-power signals of interest were recovered successfully.展开更多
基金This work was partially supported by the National Natural Science Foundation of China(Grant Nos.71971090,71571077,and 71531009).
文摘Over the past decade,electric vehicles(EVs)have been considered in a growing number of models and methods for vehicle routing problems(VRPs).This study presents a comprehensive survey of EV routing problems and their many variants.We only consider the problems in which each vehicle may visit multiple vertices and be recharged during the trip.The related literature can be roughly divided into nine classes:Electric traveling salesman problem,green VRP,electric VRP,mixed electric VRP,electric location routing problem,hybrid electric VRP,electric dial-a-ride problem,electric two-echelon VRP,and electric pickup and delivery problem.For each of these nine classes,we focus on reviewing the settings of problem variants and the algorithms used to obtain their solutions.
基金supported in part by the National Key R&D Program of China (No.2019YFB2203202)National Natural Science Foundation of China (Nos.62075026 and 61875028)+3 种基金National Research Foundation of China (No.61404130403)Program for Innovative Talents in Universities of Liaoning Province (No.LR2019017)Dalian Science and Technology Innovation Foundation (No.2018J11CY006)Fundamental Research Funds for the Central Universities(Nos.DUT18ZD106, DUT18GF102, and DUT18LAB20)。
文摘Radio frequency(RF) self-interference is a key issue for the application of in-band full-duplex communication in beyond fifth generation and sixth generation communications.Compared with electronic technology, photonic technology has the advantages of wide bandwidth and high tuning precision, exhibiting great potential to realize high interference cancellation depth over broad band.In this paper, a comprehensive overview of photonic enabled RF self-interference cancellation(SIC)is presented.The operation principle of photonic RF SIC is introduced, and the advances in implementing photonic RF SIC according to the realization mechanism of phase reversal are summarized.For further realistic applications, the multipath RF SIC and the integrated photonic RF SIC are also surveyed.Finally, the challenges and opportunities of photonic RF SIC technology are discussed.
基金National Natural Science Foundation of China(62075026, 61875028)National Key Research and Development Program of China (2019YFB2203202)+2 种基金Liaoning Revitalization Talents Program (XLYC2002111)Program for Liaoning Excellent Talents in University(LR2019017)Fundamental Research Funds for the Central Universities (DUT22ZD202)。
文摘In-band full-duplex(IBFD) technology can double the spectrum utilization efficiency for wireless communications,and increase the data transmission rate of B5G and 6G networks and satellite communications. RF self-interference is the major challenge for the application of IBFD technology, which must be resolved. Compared with the conventional electronic method, the photonic self-interference cancellation(PSIC) technique has the advantages of wide bandwidth, high amplitude and time delay tuning precision, and immunity to electromagnetic interference.Integrating the PSIC system on chip can effectively reduce the size, weight, and power consumption and meet the application requirement, especially for mobile terminals and small satellite payloads. In this paper, the silicon integrated PSIC chip is presented first and demonstrated for IBFD communication. The integrated PSIC chip comprises function units including phase modulation, time delay and amplitude tuning, sideband filtering, and photodetection, which complete the matching conditions for RF self-interference cancellation. Over the wide frequency range of C, X, Ku, and K bands, from 5 GHz to 25 GHz, a cancellation depth of more than 20 dB is achieved with the narrowest bandwidth of 140 MHz. A maximum bandwidth of 630 MHz is obtained at a center frequency of10 GHz. The full-duplex communication experiment at Ku-band by using the PSIC chip is carried out. Cancellation depths of 24.9 dB and 26.6 dB are measured for a bandwidth of 100 MHz at central frequencies of 12.4 GHz and14.2 GHz, respectively, and the signal of interest(SOI) with 16-quadrature amplitude modulation is recovered successfully. The factors affecting the cancellation depth and maximum interference to the SOI ratio are investigated in detail. The performances of the integrated PSIC system including link gain, noise figure, receiving sensitivity, and spurious free dynamic range are characterized.
基金supported in part by National Natural Science Foundation of China(Nos.62475030,62075026 and 61875028)National Key R&D Program of China(No.2019YFB2203202),Liao Ning Revitalization Talents Program(XLYC2002111)+1 种基金Open Project of State Key Laboratory of Transient Optics and Photonics,Chinese Academy of Sciences(SKLST202204)International Exchange Fund for the“Excellent Co-creation Plan”.
文摘Compared with the traditional frequency division duplex and time division duplex,the in-band full-duplex(IBFD)technology can double the spectrum utilization efficiency and information transmission rate.However,radio frequency(RF)self-interference remains a key issue to be resolved for the application of IBFD.The photonic RF self-interference cancellation(SIC)scheme is endowed with the advantages of wide bandwidth,high amplitude and time delay tuning precision,and immunity to electromagnetic interference.To meet the requirements of the new generation of mobile terminals and satellite payloads,the photonic RF SIC system is desired to be miniaturized,integrated,and low power consumption.In this study,the integrated photonic RF SIC scheme was proposed and demonstrated on a silicon-based platform.By utilizing the opposite bias points of the on-chip dual Mach-Zehnder modulators,the phase inversion relationship for SIC was realized over a broad frequency band.The time delay structure combining the optically switched waveguide and compact spiral waveguide enables continuous tuning of time over a wide bandwidth.The optical amplitude adjuster provides efficient amplitude control with a large dynamic range.After being packaged with optical,direct current,and RF design,the photonic RF SIC chip exhibits the interference cancellation capabilities across L,S,C,X,Ku,K,and Ka bands.In the S and C bands,a cancellation depth exceeding 20 dB was measured across a bandwidth of 4.8 GHz.An impressive cancellation depth of over 40 dB was achieved within a bandwidth of 80 MHz at a central frequency of 2 GHz.For the application of over-the-air IBFD communication at the newly promulgated center frequency of 6 GHz for 5G communication,the cancellation depth of 21.7 dB was demonstrated in the bandwidth of 100 MHz,and the low-power signals of interest were recovered successfully.
